RE: Brushed motor equivalent size
I really have no clue since no distributor seems able to post max. amp ratings for any brushed motor! I know Speed 400's are about 65g and rated for 75W-100W.. Speed 480's (103g) can do 20A/200W....big 12v 600's (220g) are probably good for no more than 20A-30A... so we seem to be in the order of 1W-2W/g.